# File lib/phusion_passenger/platform_info/ruby.rb, line 189
        def self.rvm_ruby_string
                if in_rvm?
                        # RVM used to export the necessary information through
                        # environment variables, but doesn't always do that anymore
                        # in the latest versions in order to fight env var pollution.
                        # Scanning $LOAD_PATH seems to be the only way to obtain
                        # the information.
                        
                        # Getting the RVM name of the Ruby interpreter ("ruby-1.9.2")
                        # isn't so hard, we can extract it from the #ruby_executable
                        # string. Getting the gemset name is a bit harder, so let's
                        # try various strategies...
                        
                        # $GEM_HOME usually contains the gem set name.
                        if GEM_HOME && GEM_HOME.include?("rvm/gems/")
                                return File.basename(GEM_HOME)
                        end
                        
                        # User somehow managed to nuke $GEM_HOME. Extract info
                        # from $LOAD_PATH.
                        matching_path = $LOAD_PATH.find_all do |item|
                                item.include?("rvm/gems/")
                        end
                        if matching_path
                                subpath = matching_path.to_s.gsub(/^.*rvm\/gems\//, '')
                                result = subpath.split('/').first
                                return result if result
                        end
                        
                        # On Ruby 1.9, $LOAD_PATH does not contain any gem paths until
                        # at least one gem has been required so the above can fail.
                        # We're out of options now, we can't detect the gem set.
                        # Raise an exception so that the user knows what's going on
                        # instead of having things fail in obscure ways later.
                        STDERR.puts "Unable to autodetect the currently active RVM gem " +
                                "set name. Please contact this program's author for support."
                        exit 1
                end
                return nil
        end